accretion disk

noun

Definition of accretion disk 

: a disk of usually gaseous matter surrounding a massive celestial object (such as a black hole) in which the matter gradually spirals in toward and accretes onto the object as a result of gravitational attraction

Examples of accretion disk in a Sentence

Recent Examples on the Web

In these cases, matter from the star falls into its ultradense partner, and the swirling gas forms what's known as an accretion disk around the black hole's maw. National Geographic, "Thousands of Black Holes May Lurk at the Galaxy's Center," 4 Apr. 2018 Theorists suspected an unseen orbiting companion was sucking in material from the star, creating a superhot accretion disk blazing with x-rays. Adrian Cho, Science | AAAS, "Hawking’s final quest: saving quantum theory from black holes," 20 Mar. 2018 Somehow, the accretion disk of mostly hydrogen gas that surrounded the early sun coalesced into the rocky planets and asteroids in the solar system, and those protoplanets shed some elements in a process known as devolatilization. Jay Bennett, Popular Mechanics, "Scientists Create Most Accurate Estimate of Earth's Composition," 18 Sep. 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'accretion disk.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

See More

First Known Use of accretion disk

1972, in the meaning defined above

Keep scrolling for more

Learn More about accretion disk

Share accretion disk

Statistics for accretion disk

Look-up Popularity

Time Traveler for accretion disk

The first known use of accretion disk was in 1972

See more words from the same year

More from Merriam-Webster on accretion disk

Britannica.com: Encyclopedia article about accretion disk

Comments on accretion disk

What made you want to look up accretion disk? Please tell us where you read or heard it (including the quote, if possible).

WORD OF THE DAY

lying above or upon

Get Word of the Day daily email!

Test Your Vocabulary

Words from Greek and Roman Mythology Quiz

  • the-triumph-of-venus-by-alessandro-magnasco
  • Boreal comes from the name of the ancient Greek god of which wind?
How Strong Is Your Vocabulary?

Test your vocabulary with our 10-question quiz!

TAKE THE QUIZ
Word Winder's CrossWinder

Test Your Knowledge - and learn some interesting things along the way.

TAKE THE QUIZ

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!